Tolerable Limits Research Articles

Understanding the detrimental effects of heavy metal pollution in shrimp farming and treatment methods – a review

Abstract High levels of heavy metals in the environment pose a significant risk to the aquatic ecosystem and its organisms. The non-biodegradable nature and lengthy persistence of heavy metals in the environment lead to toxicity in shrimp. Using aquatic animals as bio-indicators of metal contamination provides valuable data on acute and chronic toxicity in aquatic species and environmental quality. This review aims to provide insights into the sources, impacts, diseases and mitigation strategies related to heavy metal pollution in shrimp farming and the dangers to humans. Shrimp growth and development at each stage exhibit distinct responses to toxicity, which can vary depending on the species, types of metals, their mechanisms of action, as well as the concentration of heavy metals and duration of exposure. While several heavy metals are considered essential nutrient elements that enhance shrimp growth and feed efficiency, exceeding the maximum tolerable limit threatens shrimp health, human consumers, and ecological systems’ stability. Shrimp species subjected to lethal toxic metal concentrations experience significant effects on accumulation in histopathology. Heavy metal toxicity has been linked to high mortality rates, malformation rates, oxidative stress, moulting issues, and decreased reproduction with increasing concentrations in shrimp. Various methods have been reported for removing heavy metal ions from aquatic environments, including filtration, adsorbents, removal efficacy, operating conditions, and the pros and cons of each technique. Therefore, this review provides an overview of how heavy metals can affect shrimp physiology and dangers to consumers. It aims to increase awareness about the importance of preventing and regulating their contamination in aquatic environments.

Limitations of Plant Stress Tolerance upon Heat and CO2 Exposure in Black Poplar: Assessment of Photosynthetic Traits and Stress Volatile Emissions.

Volatile organic compounds (VOCs) emitted by plants may help in understanding the status of a plant's physiology and its coping with mild to severe stress. Future climatic projections reveal that shifts in temperature and CO2 availability will occur, and plants may incur the uncoupling of carbon assimilation and synthesis of key molecules. This study explores the patterns of emissions of key VOCs (isoprene, methanol, acetaldehyde, and acetic acid) emitted by poplar leaves (more than 350) under a combined gradient of temperature (12-42 °C) and air CO2 concentration (400-1500 ppm), along with measurements of photosynthetic rates and stomatal conductance. Isoprene emission exhibited a rise with temperature and CO2 availability, peaking at 39 °C, the temperature at which methanol emission started to peak, illustrating the limit of stress tolerance to severe damage. Isoprene emission was uncoupled from the photosynthesis rate, indicating a shift from the carbon source for isoprene synthesis, while assimilation was decreased. Methanol and acetaldehyde emissions were correlated with stomatal conductance and peaked at 25 °C and 1200 ppm CO2. Acetic acid emissions lacked a clear correlation with stomatal conductance and the emission pattern of its precursor acetaldehyde. This study offers crucial insights into the limitations of photosynthetic carbon and stress tolerance.

Electrochemical Characterization of Electrodeposited Copper in Amine CO2 Capture Media.

This study explores the stability of electrodeposited copper catalysts utilized in electrochemical CO2 reduction (ECR) across various amine media. The focus is on understanding the influence of different amine types, corrosion ramifications, and the efficacy of pulse ECR methodologies. Employing a suite of electrochemical techniques including potentiodynamic polarization, linear resistance polarization, cyclic voltammetry, and chronopotentiometry, the investigation reveals useful insights. The findings show that among the tested amines, CO2-rich monoethanolamine (MEA) exhibits the highest corrosion rate. However, in most cases, the rates remain within tolerable limits for ECR operations. Primary amines, notably monoethanolamine (MEA), show enhanced compatibility with ECR processes, attributable to their resistance against carbonate salt precipitation and sustained stability over extended durations. Conversely, tertiary amines such as methyldiethanolamine (MDEA) present challenges due to the formation of carbonate salts during ECR, impeding their effective utilization. This study highlights the effectiveness of pulse ECR strategies in stabilizing ECR. A noticeable shift in cathodic potential and reduced deposit formation on the catalyst surface through periodic oxidation underscores the efficacy of such strategies. These findings offer insights for optimizing ECR in amine media, thereby providing promising pathways for advancements in CO2 emission reduction technologies.

On a Closer Look of a Doppler Tolerant Noise Radar Waveform in Surveillance Applications.

The prevalence of Low Probability of Interception (LPI) and Low Probability of Exploitation (LPE) radars in contemporary Electronic Warfare (EW) presents an ongoing challenge to defense mechanisms, compelling constant advances in protective strategies. Noise radars are examples of LPI and LPE systems that gained substantial prominence in the past decade despite exhibiting a common drawback of limited Doppler tolerance. The Advanced Pulse Compression Noise (APCN) waveform is a stochastic radar signal proposed to amalgamate the LPI and LPE attributes of a random waveform with the Doppler tolerance feature inherent to a linear frequency modulation. In the present work, we derive closed-form expressions describing the APCN signal's ambiguity function and spectral containment that allow for a proper analysis of its detection performance and ability to remove range ambiguities as a function of its stochastic parameters. This paper also presents a more detailed address of the LPI/LPE characteristic of APCN signals claimed in previous works. We show that sophisticated Electronic Intelligence (ELINT) systems that employ Time Frequency Analysis (TFA) and image processing methods may intercept APCN and estimate important parameters of APCN waveforms, such as bandwidth, operating frequency, time duration, and pulse repetition interval. We also present a method designed to intercept and exploit the unique characteristics of the APCN waveform. Its performance is evaluated based on the probability of such an ELINT system detecting an APCN radar signal as a function of the Signal-to-Noise Ratio (SNR) in the ELINT system. We evaluated the accuracy and precision of the random variables characterizing the proposed estimators as a function of the SNR. Results indicate a probability of detection close to 1 and show good performance, even for scenarios with a SNR slightly less than -10 dB. The contributions in this work offer enhancements to noise radar capabilities while facilitating improvements in ESM systems.

Teachers’ and parents’ perspectives on citizenship education in Turkey: Consensus and disagreements

Citizenship education (CE) in Turkey holds a pivotal role in shaping the civic consciousness of forthcoming generations. This study employs Q methodology to analyze the perspectives of teachers and parents regarding CE in Turkey, examining their viewpoints in the context of the political structure. The research reveals both consensus and disagreement among teachers and parents. Despite significant differences between teachers and parents, a consensus emerges on the importance of reinforcing national identity through CE. Moreover, there is a prevalent perspective on citizenship that exhibits limited tolerance for differences. The perspectives identified in the study reflect the political polarization present in Turkey. Some perspectives adopt a nationalist understanding rooted in Islamic foundations, influenced by the political power in the country, while others adhere to a secular nationalism based on the principles of Kemalism. These findings underscore the necessity for all facets of CE to embrace a more comprehensive perspective that promotes tolerance and democratic values.

Mitigation of Mycotoxins in Food-Is It Possible?

Among microorganisms found in food, fungi stand out because they are adaptable and competitive in a large range of water activities, temperatures, pHs, humidities and substrate types. Besides sporulating, some species are toxigenic and produce toxic metabolites, mycotoxins, under adverse biotic and abiotic variables. Microorganisms are inactivated along the food chain, but mycotoxins have stable structures and remain in ready-to-eat food. The most prevalent mycotoxins in food, which are aflatoxins, fumonisins, ochratoxin A, patulin, tenuazonic acid, trichothecenes and zearalenone, have maximum tolerable limits (MTLs) defined as ppb and ppt by official organizations. The chronic and acute toxicities of mycotoxins and their stability are different in a chemical family. This critical review aims to discuss promising scientific research that successfully mitigated levels of mycotoxins and focus the results of our research group on this issue. It highlights the application of natural antifungal compounds, combinations of management, processing parameters and emergent technologies, and their role in reducing the levels and bioaccessibility. Despite good crop management and processing practices, total decontamination is almost impossible. Experimental evidence has shown that exposure to mycotoxins may be mitigated. However, multidisciplinary efforts need to be made to improve the applicability of successful techniques in the food supply chain to avoid mycotoxins' impact on global food insecurity.

Orexinergic Receptor Antagonists as a New Therapeutic Target to Overcome Limitations of Current Pharmacological Treatment of Insomnia Disorder.

Insomnia disorder is a common condition that is considered a risk factor for multiple physical and mental disorders, contributing to reduced quality of life and increased healthcare expenditures. Although cognitive behavioral therapy (CBT) is typically recommended as the primary intervention, its accessibility is hindered by limited resources, prompting the prevalent use of pharmacological interventions as the primary treatment in clinical settings. This study reviews the benefits and risks of current pharmacological treatments for insomnia, with special reference to the orexinergic system as a novel therapeutic target for treatment. The prescription of GABAergic mechanism enhancers (benzodiazepine (BZD) and "Z drugs") has shown efficacy in short-term insomnia treatment (less than 4 weeks), however, concerns arise regarding their long-term effectiveness, unfavorable tolerability and safety profiles, including the potential for dependency. Drugs with antihistamine properties, including certain antidepressants and antipsychotics, exhibit short-term efficacy but have documented tolerability limitations, especially in the elderly. The use of melatonin, available in various formulations, lacks comprehensive long-term data. Dual orexin receptor antagonists (DORAs) such as daridorexant, lemborexant, and suvorexant, represent a novel approach to insomnia treatment by inhibiting wakefulness rather than enhancing sedation. As the only DORA approved for insomnia treatment by the European Medicines Agency (EMA) and Food and Drug Administration (FDA), daridorexant has demonstrated sustained efficacy over a 12-month period, improving nocturnal sleep parameters and daytime functionality, with a favorable safety and tolerability profile.

Artificial light at night bans Chaoborus from vital epilimnetic waters

Artificial light at night (ALAN) is known to affect organisms in terrestrial ecosystems and adjacent litoral habitats. In the present study, we tested the effect of ALAN on the spatial distribution of organisms in open waters, using the insect larvae of Chaoborus flavicans as an example. During the day C. flavicans typically hide from visually hunting fish in deep, dark, anoxic waters. On safer nights, they forage in rich subsurface waters. Nighttime field tests revealed that light from an HPS street lamp mounted on a boat anchored in open water attracted planktivorous fish, but deterred planktonic Chaoborus from rich but risky surface waters. Chaoborus did not descend to the safest, anoxic hypolimnion, but remained in hypoxic mid-depth metalimnion, which does not appear to be a perfect refuge. Neither light gradient nor food distribution fully explained their mid-depth residence under ALAN conditions. A further laboratory test revealed a limited tolerance of C. flavicans to anoxia. Half of the test larvae died after 38 h at 9 °C in anoxic conditions. The trade-off between predation risk and oxygen demand may explain why Chaoborus did not hide in deep anoxic waters, but remained in the riskier metalimnion with residual oxygen under ALAN conditions.

Maximum consensus model with individual tolerance and mixed DEA prospect cross-efficiency for multi-attribute group decision-making

Experts are mostly not completely rational, and they generally exhibit different psychological attitudes and behaviors in multi-attribute group decision-making (MAGDM), which may lead to actual decisions deviating from the results obtained by traditional objective methods. Therefore, it is reasonable and necessary to capture individual tolerance and risk attitudes of experts when dealing with MAGDM problems. To achieve this intention, we design a MAGDM method that combines the maximum consensus model with individual tolerance and mixed DEA prospect cross-efficiency. In the consensus reaching process (CRP), we devise a maximum consensus model with individual tolerance, which can achieve a high consensus level with limited expert tolerance. In the selection process, we first define the prospect aggressive and benevolent cross-efficiency functions. Then, a mixed DEA prospect cross-efficiency ranking method is proposed, which reflects the attitudes of DMs (decision-makers) towards losses and gains. Moreover, this method avoids DMs’ hesitation and trouble in choosing between aggressive and benevolent DEA models. Subsequently, the algorithm and framework for the MAGDM method based on individual tolerance and risk attitude are proposed. Finally, the applicability of our method can be validated by an illustrative example. Sensitivity analysis and comparative analysis are supplied to indicate the rationality and superiority of our developed method.

THE IMPACT OF DIGITAL TRANSFORMATION AND LEADERSHIP ON ORGANIZATIONAL RESILIENCE IN DISTANCE EDUCATION INSTITUTION: HIGHER-ORDER SEM APPROACH

To overcome the difficulty and unprecedented suspensions due to the COVID-19 pandemic, every organization is required to consider strategic steps to sustain, one of which is by implementing digital transformation and developing leadership capability. This study aims to determine the impact of digital transformation and leadership capability in maintaining the organization, particularly in distance education. This study used questionnaires distributed to 402 students to obtain their opinions on digital transformation, leadership capability, and organizational resilience in Universitas Terbuka, a founder of distance education institutions in Indonesia. Data were analyzed using descriptive and Higher-Order Structural Equation Modeling analysis. Based on the modelling, it is shown that the modelling had a good value of the Goodness of Fit Indicator through a standardized loading factor (SLF) more than the tolerable loading factor limit (>0.50). The Variance Extracted (VE) and Construct Reliability (CR) values also showed that the questions on every indicator used in this study were sufficiently measurable and reliable. The results of hypothesis testing indicated that there was a positive and significant impact of digital transformation and leadership capability on the organızatıonal resılıence of Universitas Terbuka.

Factors affecting iodine content of cow milk-A review

This review discusses the importance of iodine as an essential nutrient for human health and the factors that can influence the concentration of iodine in cow milk. For an adult, the daily recommended requirement of iodine is 150 µg/day and the maximum tolerable limit ranges from 600 to 1100 µg/day. Cow milk is a significant source of iodine in many countries, particularly in areas where iodine-rich foods are not readily available. Therefore, evaluating the variables that affect the iodine content of cow milk is important. The iodine concentration of cow milk can vary depending on several factors such as genetics, diet, environment, management practices, season, and processing. Particularly, dietary supplementation and feed composition have been identified as the most impactful on milk's iodine levels, offering a practical approach to mitigating iodine deficiency. Furthermore, environmental factors like soil and water iodine content and management practices, including the type of farming, play substantial roles. Seasonal changes also significantly affect iodine levels, with higher concentrations typically observed in winter due to different feeding practices. The iodine content of cow milk falls between 147 to 605 µg/kg and the highest value of 11100 µg/L was recorded in camel milk. Milk could supply up to 60% of the daily dietary requirement of iodine for an adult person. To fight iodine deficiency through the appropriate approach to such concerns, one must have an in-depth understanding of these issues. This review paper aims to provide a comprehensive analysis of these factors and their implications for human and public health strategies. Bangladesh Journal of Animal Science 53 (1): 1-12, 2024

Level of aflatoxins in dairy feeds, poultry feeds, and feed ingredients produced by feed factories in Addis Ababa, Ethiopia.

Aflatoxins are one of the major factors that affect the quality and safety of feeds. They can be transferred into livestock through contaminated feed and then onto humans via animal sources of food such as milk, meat, and eggs. The objective of this study was to detect and quantify the level of aflatoxins (B1, B2, G1, G2, and total aflatoxin) in dairy feeds, poultry (layer and broiler) feeds, and feed ingredients produced in Addis Ababa. A total of 42 feeds and feed ingredients consisting of dairy feeds (n = 5), poultry broiler feeds (n = 6), layer feeds (n = 6), and feed ingredients (n = 25) were collected from feed factories in the city and analyzed in fresh weigh basis. The aflatoxins were analyzed using high-performance liquid chromatography after clean-up with immunoaffinity columns. Aflatoxin B1 levels in feeds ranged from 51.66 to 370.51µg/kg in dairy cattle feed, from 1.45 to 139.51µg/kg in poultry layer feed, and from 16.49 to 148.86µg/kg in broiler feed. Aflatoxin B1 levels in maize ranged from 2.64 to 46.74µg/kg and in Niger seed cake from 110.93 to 438.86µg/kg. Aflatoxin B1 levels in wheat bran, wheat middling, and soybean were below 5µg/kg. 100% of dairy feeds, 67% of poultry layer, 67% of broiler feeds, and 24% of ingredients contained aflatoxin in levels higher than the maximum tolerable limit set by the US Food and Drug Administration and Ethiopian Standard Agency. This shows the need for strong regulatory monitoring and better feed management practices to prevent consumers of animal-source foods from significant health impacts associated with aflatoxins.

A greener, rapid and accurate microwave-assisted hydrogen peroxide digestion method for ICP-OES determination of heavy metals in pet food samples

Microwave-assisted hydrogen peroxide digestion (MW-AHPD) method for determination of Cd, As, Pb, Sn, and Cr in South African pet food samples by inductively coupled plasma-optical emission spectroscopic (ICP-OES) is reported. Multivariate tools and wheat flour certified reference material (FAP80467) assessed limiting factors and reproducibility of the methods respectively. The resulted optimum conditions were: 200 °C, 40 mins, 0.5 g, and 5 mol/L for temperature, time, sample mass and H2O2 concentration, respectively. The method demonstrated excellent accuracy (96–98%), reproducibility (≤ 2.1%) and high detection limits (0.0675–0.3765 µg/g). Then, real pet food samples made from maize, rice, vegetables, fish, and wheat were digested and concentration levels of Cd, Pb, As, Cr and Sn ranged between 11.2 and 22.6, 6.4–11.9, 3.44–13.4, 0.44–2.98 and 0.18–0.98 µg/g, respectively. The three metal ions were above the minimum tolerable limits (Cd: 10 µg/g, Pb:10 µg/g, As: 12.5 µg/g) for some of the fish and wheat based pet food according to the South African regulatory standard. Furthermore, using the AGREEPrep metric tool the method was assessed and had a score of 0.76, confirming its greenness. These findings present MW-AHPD method as an alternative for determination of heavy metals in pet food by ICP-OES.

BIOEXTRACTION OF IRON THROUGH Bacillus sp. SP10 FROM MINERAL OXIDE AND ITS APPLICATION AS PLANT MICRONUTRIENT

Iron is an essential micronutrient for all living organisms because of its critical 
 role in metabolic processes. In plants it plays a key role in the synthesis of 
 chlorophyll, some vital enzymatic and metabolic processese. However, most of 
 the iron in nature is present as precipitates or in insoluble forms. Therefore, 
 biological mechanism has been employed to mineralize Fe(III) oxides into 
 Fe(II) through microbial action to increase the availability of soluble iron. An 
 iron reducing bacterial strain was isolated based on its tolerant limits and iron 
 mineralizing ability. The strain Bacillus sp. SP10 effectively mineralized iron 
 in synthetic medium possessing 1% starch and pH 7. In a 25 day’s column 
 study, the soluble Fe(II) as micronutrient showed a gradual increase in each 
 seepage collected from different treatment columns. Similarly, the plants 
 grown on soil obtained from treatment D (i.e. 1% starch + 1% Bacillus sp. 
 SP10 inoculum + 0.25% anthraquinone-2,6-disulphonate) column displayed 
 good growth and maximum shoot length, mainly due to the increased 
 accessibility of iron through microbial mineralization. The mineralization of 
 Fe in soil was established through SEM and EDX analysis.

Abstract 6610: Metabolic patterns of pancreatic cancer cachexia: Cross-tissue lipid networks predict cachexia progression

Abstract Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of all cancer types. A key — yet poorly understood — facet in the disease state is cachexia, a multi-organ pathological state characterized by physical wasting and tissue catabolism. It occurs in 80% of PDAC patients, and to date there are no preventative or early detection methods. Cachexia leads to limited tolerance to anti-cancer therapy and contributes to disease lethality. Here, we present the first-of-its-kind systemic metabolomic analysis across cachectic stages to better understand disease progression. We used the well-established mutant KRASG12D(LSL/+) mutant p53 inducible mouse model of PDAC. Model physiology faithfully recaptures human cachexia: we observe progressive overall weight loss as well as loss of skeletal muscle and adipose tissue. As with human disease, weight loss occurs prior to loss of appetite in the animals, suggesting physiological changes independent of nutrition. Importantly, our model captures the period prior to weight loss (pre-CAC), as well as early-CAC (<10% weight loss) and late-CAC (>10% weight loss). We profiled the metabolomes of the pancreas, interstitial fluid, plasma, liver, 3 different adipose tissues, and 3 skeletal muscles, from male and female mice, control and tumor-bearing, across all 3 stages of cachexia. Each tissue has a unique metabolic trajectory across cachexia stages; pathway and correlation analyses showed a particular emphasis on lipid alterations in peripheral tissues. Strikingly, we find systemic metabolic changes prior to tissue wasting, including rewiring in the liver before the presence of metastases. This indicates systemic alterations as early as pre-CAC. We therefore used computational modeling to identify metabolites that may be participating in cross-tissue networks. A key finding, confirmed by 13C tracing, was the circulation of lactate and glucose and their uptake by the liver and pancreas. Network maps also suggest lipid rewiring in distal tissues, changes in abundances of these same lipid species in plasma, and their consequent alterations in the tumor and liver. A fundamental question remains: can we predict cachexia development before the manifestation of symptoms? We used feature selection algorithms based on statistical learning, training the models only on a subset of data. Specific sphingolipids and triglycerides were the key lipid species that distinguished control and pre-CAC. We find that the model — trained only on pre-CAC — is able to determine early-CAC with an 85% accuracy and late-CAC with a 90% accuracy. Thus, a limited set of metabolites that are altered in pre-CAC could have predictive value for future cachexia development. Overall, our work provides a resource for the field and advances our understanding of systemic metabolism in PDAC cachexia. We hope this will lay the foundation for cachexia prevention and treatment. Citation Format: Deepti Mathur, Blanca Majem, Courtney Beaulieu, Lucas Dailey, Sarah Jeanfavre, Joao Xavier, Clary Clish, Nada Kalaany. Metabolic patterns of pancreatic cancer cachexia: Cross-tissue lipid networks predict cachexia progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6610.

Assessment of the trueness of additively manufactured mol3% zirconia crowns at different printing orientations with an industrial and desktop 3D printer compared to subtractive manufacturing

ObjectivesThis study endeavours to investigate the effect of printing orientation on the trueness of additively manufactured molar zirconia crowns. The areal surface roughness and the characteristics of the marginal regions of the crowns were also considered. MethodsTwelve molar crowns were manufactured at 0°, 45°, and, 90° printing orientations in a Lithoz and AON zirconia printer, respectively. Twelve milled crowns were used as a comparison. Samples were scanned and analysed in metrology software to determine the trueness of the groups. Regions of interest were defined as the margins, intaglio surface and contact points. Areal surface roughness and print layer thickness were further analysed using a confocal laser scanning microscope. ResultsThe results indicate that there are clear differences between the investigated desktop (AON) and industrial (Lithoz) 3D printer. The 45° Lithoz group is the only sample group showing no significantly different results in trueness for all regions analysed compared to the milled group. Areal surface roughness analysis indicates that the print layers in the marginal regions are within clinically tolerable limits and surface characteristics. ConclusionsThe printing orientation for zirconia crowns is critical to trueness, and differences are evident between different AM apparatuses. Considerations for design and orientation between different apparatuses should therefore be considered when utilising direct additive manufacturing processes. The areal surface roughness of the marginal regions is within acceptable clinical limits for all manufacturing processes and print orientations considered. Clinical significanceThe materials and apparatuses for additive manufacturing of zirconia crowns are now clinically acceptable from the perspective of the trueness of a final crown for critical functional surfaces and areal surface roughness of the marginal regions.

Total mercury in three small tunas from southeastern Brazil: Stable isotope relations and human risk assessment

Mercury (Hg) bioaccumulation can be highly variable in marine species. Its concentration is influenced by several physico-chemical and biotic processes, including size, age, diet composition and foraging habitats. Herein, we addressed total mercury (THg) concentrations in three small tuna species in Brazil: the frigate tuna Auxis thazard, the little tunny Euthynnus alletteratus and the skipjack tuna Katsuwonus pelamis. Samples were collected from commercial landings in the SE Brazilian coast from 2017 to 2019. The influence of trophic ecology and habitat preference on Hg accumulation was assessed through stable isotope [carbon (δ13C) and nitrogen (δ15N)] measurements. Additionally, the human health risk regarding the species consumption was assessed by the estimated weekly intake (EWI) and the provisional tolerable weekly intake (PTWI) for total consumers, adult men and adult women. Variables such as size and age were positively correlated to Hg, due to the bioaccumulation process. Trophic position appears to positively influence the mercury concentrations for A. thazard and K. pelamis, since relationship between δ15N and THg was significant. For E. alletteratus, the lack of relationship suggests that δ15N values do not vary much among adult fish (> 300 mm). Muscle THg concentrations in the three species did not exceed the established tolerable limit for mercury by Brazilian and international organs, as indicated by the %PTWI. This finding suggests that the consumption of those species caught off southeast Brazil at the considered amounts does not present a risk for healthy adults.

Effects of foliar application of Zn combined with organic matters on Cd accumulation and its chemical forms in rice.

Rice consumption is a key Cd exposure pathway, which poses a health risk to humans. Reducing cadmium (Cd) concentrations in rice remains challenging. In this study, a pot experiment was conducted to examine the effects of foliar spray of Zn combined with organic matters (including Zn-lysine (Zn-Lys), Zn-fulvic acid (Zn-FA), Zn-amino acid (Zn-AA), and Zn combined with glutathione (Zn + GSH)) on Cd accumulation in rice grains. Compared with the control group, all treatment groups exhibited reduced Cd concentration in rice grains, while improving plant growth, and reducing Cd transport from other tissues to the grains. Zn-FA was found to be the most effective fertilizer, which considerably reduced Cd concentrations in grains from 0.77 ± 0.068 to 0.14 ± 0.021mg/kg and yielded reductions of up to 81%, which is within the Chinese food maximum tolerable limit of 0.2mg/kg. Furthermore, the analysis of the chemical forms of Cd of rice tissues indicated that the treatment groups had increased proportions of integrated with pectates and protein in the stems. Except for the group treated with Zn-Lys spray, the percentages of undissolved Cd phosphate in the leaves were increased in all treatment groups, which reduced Cd toxicity to rice plants. The foliar application of Zn combined with organic matters may be a promising strategy to decrease Cd concentration in rice grains cultivated in severely Cd-contaminated agricultural soil, particularly in the karst area in southwest China with limited available cultivable agricultural land.

Comparative Studies of the Physico-Mechanical Characterization of Ugwuoba Clay with Admixtures of Corncob and Sugarcane Bagasse Ashes

An investigation into the effects of combustible materials on the refractory properties of Ugwuoba clay, using sugarcane bagasse ash and corncob ash has been undertaken. Ugwuoba clay was sourced from Ugwuoba town in Oji River Local Government Area of Enugu State. Sugarcane bagasse were collected at Lokpanta, a Fulani settlement in Okigwe Community, Imo State, while corncobs were collected at New Artisan Market in Enugu Metropolis. The clay was processed using standard beneficiation and purification procedures at the Ceramics Department of Projects Development Agency (PRODA), Enugu. The sugarcane bagasse and corncobs were each and separately calcined into amorphous ash by heating in a furnace at 650oC. The refractory blends were compounded at the ratio of 90:10, 80:20, 70:30, and 60:40 for Ugwuoba clay (UGC) to Sugarcane Bagasse Ash (SBA) and Ugwuoba Clay (UGC) to Corncob Ash (CCA) separately and respectively. These blends were subsequently molded into the standard test pieces for the various properties determination and subjected to firing at temperatures of 900oC, 1000oC, 1100oC and 1200oC. Thereafter, the fired samples were characterized for fired shrinkages, total shrinkages, apparent porosities, water absorption coefficients, apparent densities, bulk densities and moduli of rupture. The results obtained for each of the blends showed that the values were within the tolerable limits for industrial refractories with the 10%SBA and the 20%CCA blends showing the best results. Comparatively however, the 10%SBA produced the better of these properties than the 20%CCA. A conclusion is drawn to the effect that both sugarcane bagasse ash and corncob ash can serve as good organic admixtures for refractory bricks production for the lining of melting furnaces in the metals industry, hence opening new frontiers for recycling of these agricultural wastes for environmental safety and economic development in Nigeria.

Heavy Metal-Related Health Risk Assessment of Cultivated Plants Around a Cement Factory in Sokoto North Western, Nigeria

The pollution of the environment by cement manufacturing companies is becoming a global concern, particularly in developing nations. This study assessed the levels of heavy metals and their associated health risks in sugarcanes (Saccharum officinarum), tomatoes (Solanum lycopersicum), and almonds (Prunus dulcis) cultivated in the vicinity of a cement factory in Sokoto, Nigeria. Samples of these plants were collected, treated, and then assayed for lead (Pb), copper (Cu), cadmium (Cd), and zinc (Zn) using atomic absorption spectroscopy (AAS). The values obtained were compared against the permissible limits established by the World Health Organization (WHO), and these results were used to estimate the potential health risks associated with consuming these plants. The findings revealed that both the Solanum lycopersicum and Saccharum officinarum contained non-tolerable levels of Cu, Cd, Pb, and Zn, while Prunus dulcis had non-tolerable levels of Zn only. Additionally, the concentrations of individual heavy metals in each of the three plant species showed a significant difference (p ≤ 0.05) from the respective WHO standards. The estimated daily intake (EDI) and target hazard quotient (THQ) for all the heavy metals were within the recommended limits, except for the EDI of Pb in Saccharum officinarum and the THQ of Pb in Solanum lycopersicum. The health risk index (HRI) for all the heavy metals in the three plants exceeded the tolerable limit (> 1). These findings indicate that daily consumption of these plants may pose health hazards. Therefore, the practice of cultivating plants in the vicinity of cement factories should be discouraged.